1. Field of the Invention
The present invention relates to the field of connectors for components having a high number of connection elements, formed by portions of flexible or rigid conductors.
2. Description of the Prior Art
The connection of such a component with the circuits or equipment in which it is used is most often carried out conductor by conductor, by processes such as soldering or wrapping for example and the time spent on each single operation may be justified in the case where the desired connection is permanent.
On the other hand, in the case where the component must be removable, either for replacement thereof after it becomes unserviceable, or for manufacturing tests or checks, the costs caused by the connection operations may be very high, and may appear very often as inadmissible. These cost constraints are particularly marked for components known as "integrated circuits," which are in the form of parallelepipedic cases having, on two of their large facing faces, a plurality of rigid connection conductors or "lugs," whose number may reach several tens.
In the case of manufacturing checks and machines for the industrial sorting of these components, connecting devices have had to be designed and proposed simultaneously providing connection of all of the lugs, by introducing them with a certain frictional contact, into an assembly of contact elements housed in support blocks made from an insulating material. However, in view of the high introduction force required in the case of a large number of lugs, connectors have been proposed of the so-called "zero insertion force" type, where the connection operation takes place in two steps, i.e. a step for introducing, without friction, the lugs into the contact elements, provided in the form of resilient twin-legged clips in which the lugs may freely penetrate in the open position, and a step for simultaneously clamping all the clips, by bringing together the legs of each clip of the assembly under the action of a common mobile pusher made from an insulating material.
However, the lugs of the integrated circuits to be connected present, in their disposition along the case of these latter, erratic-type geometric irregularities due on the one hand to manufacturing tolerances and, on the other hand, to accidental bends or twists during storage or use.
This is why there has been proposed, in the prior art, a solution in which the mobile pusher providing the clamping does not act directly on the legs of each clip, but on levers which are associated therewith, and which transmit the clamping forces to the legs of the clip with a possibility of adapting, by elasticity, the amplitude of the drawing together of the legs, to the erratic differences of position of the lugs.
But this known solution assigns to the same mechanism used, in a harmful way, multiple functions by using for example, for forming the levers, portions of the contact zones of the legs and, for forming the elements endowed with elasticity ensuring adaptation of the amplitudes, the same resilient part which ensures opening of the clip.
This confusion between the various functions of the mechanism have the serious drawback of not enabling the best results to be obtained that are normally obtainable and, moreover, leads to increasing the transverse bulk of the connector, the levers causing the clamping then being transversal.
FIG. 1 shows, in a general view, an integrated circuit connector of the prior art. The connector is formed from an insulating block 1, formed from three plates superimposed in tiers, and form a plurality of contact elements 2. The lower baseplate 3 assumes the function of support for the whole of the connector, forming the base thereof and supporting the contact elements. The upper plate 4 ensures the function of guiding the lugs 5 of the integrated circuit 6. The intermediate plate 7 is movable longitudinally, and may by translation in this direction, occupy two positions, by action on the circular cam 8, comprising a flattened part 9 and controlled by lever 10.
The operation of such connector is as follows. In the introduction position, the intermediate plate 7 has its openings 11 aligned with the openings 12 of the guiding upper plate 4. Lugs 5 of the integrated circuit may be easily introduced into the openings 11 and 12 since the contact elements are subjected to no bending force on the part of the intermediate plate 7.
In the clamping position, obtained by rotation of cam 8 under the action of lever 10, the intermediate plate 7 moves in the direction of arrow 13, applying its pushers 14 laterally on contacts 2. The latter then bend and provide clamping of lugs 5 and thus their electric connection. Such a connector presents no possibility of geometric adaptation of each contact to each lug, and the contact resistances obtained spread over a large range of values inadmissible in use.
FIG. 2 shows, in two partial views 2A and 2B, the two operating steps of the connector of FIG. 1, but provided with other contact elements of the prior art. In a three-tier structure in accordance with FIG. 1, with the same elements bearing the same reference numbers, the contact elements 2 are in the form of clip with twin legs 20 and 21, connected by a resilient connecting base allowing, moreover, connection with a user circuit by means of a lug (not shown). The end of each leg carries a perpendicularly disposed lateral lever 22 and 23, these two levers bearing on the opposite edges of the upper plate 4 and movable intermediate plate 7.
The operation of such a connector uses the same translation movement of the intermediate plate 7 in the direction of arrow 13 as in FIG. 1, but the clamping lip 2 effects two simultaneous movements.
In the open position of FIG. 2A, the legs 20,21 of the clip are spaced apart by an angle A and introduction of the lug whose contour 24 is shown with a broken line, is possible. In the clamping position shown in FIG. 2B, the respective edges of openings 11 and 12 of plates 7 and 4, having effected their relative movement, exert a bearing force on the lateral levers 22 and 23. This force produces two results, namely the two legs of the clip are successively drawn together until they contact lug 24 and then, after contact, the legs 20, 21 of the clip are twisted about the contact points 24 and 26 with the lug 24. This twisting, which allows the geometrical adaptation of each contact clip with each lug 24, is thus required of legs whose function is structurally different, i.e. that of clips for contacts. Similarly, the contact regions 25, 26 themselves assume, in addition to that of electric contact, two other functions, i.e. that as carriers for levers 22, 23 and points of rotation 25, 26. These dual functions, in the prior art, as has already been mentioned above, are harmful.